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Why Is My AC Running Constantly But Not Cooling?

One Hour Air Conditioning & Heating technicians standing in front of a service van, ready to provide expert HVAC services in Birmingham, AL. Why Is My AC Constantly Running but Not Cooling?

Residents of Birmingham, Alabama, depend on air conditioning to stay comfortable during the hot, humid summers. If your AC is constantly running but not cooling, you want a reliable, fast solution to restore indoor comfort.

One Hour Air Conditioning & Heating of Birmingham is known for its prompt, dependable service. We are committed to same-day service and customer satisfaction, operating according to our promise: We’re always on time, or you don’t pay a dime.

Common Reasons for Air Conditioner Malfunction

Heating, ventilation and air conditioning systems get a heavy workout during the summer months in Birmingham. Poorly maintained systems break down more often and use more energy to run. Common reasons for HVAC systems to run for long periods but not cool include:

  • Clogged filters
  • Low refrigerant
  • Dirty coils
  • Incorrect thermostat settings
  • Improperly sized units
  • Leaking or blocked ducts

Dirty or Clogged Filters

HVAC technicians cite dirty filters as one of the most common reasons for air conditioner malfunctions. Filters capture airborne particulates and keep them from entering ducts and your living space. Over time, filters become embedded with debris, such as hair, pollen, animal dander, insect parts and dust. Clogged filters prevent air from flowing through ducts, which reduces airflow into the living space. The compressor must work harder to produce conditioned air, which can overtax the system. You may notice your AC constantly running, not blowing cool air, turning on more frequently or not turning on at all.

Your HVAC owner’s manual explains how to clean or replace your filter. Most manufacturers recommend cleaning filters approximately every three months. However, if you live in an area with poor outdoor air quality or have pets, you should clean your filter more often. Our technicians check and clean filters during a seasonal maintenance checkup. We often recommend upgrading to a high-quality filter that captures smaller particulates to improve the quality of your indoor air.

Low RefrigerantOne Hour Air Conditioning & Heating technician performing AC repair in Birmingham, AL, ensuring efficient cooling and reliable system operation.

Each HVAC unit is charged with a precise amount of refrigerant so it runs efficiently and dependably. A refrigerant leakcan affect the system’s performance. You may notice that it constantly runs or does not cool effectively.

Refrigerants must be handled by trained professionals. The experienced technicians of Birmingham’s One Hour Air Conditioning & Heating can check the refrigerant level and look for leaks. Our technicians will repair leaks and adjust the amount of refrigerant to get your system running properly.

Dirty Coils

Refrigerant flows through coils absorbing and releasing heat as part of the refrigeration cycle. Over time, dust and other pollutants can settle on coils, which affects heat transfer. In a split system, the condenser coils are outside, and the evaporator coils are inside the air handler.

Symptoms of dirty coils include frequent starting and stopping without cooling, blowing warm air through ducts or not turning on. When coils are dirty, the water vapor in the air flowing over the coils can turn to ice, which can cause your system to run longer or stop working.

Coils are delicate components that should be cleaned by a trained HVAC professional. During a maintenance checkup, our technicians inspect and clean coils to ensure your system runs safely and efficiently.

Improperly Sized Systems

Proper sizing is critical to performance. Undersized units run for long periods to maintain comfortable temperature and humidity levels. Oversized units start and stop frequently. They reach the set temperature quickly without removing enough moisture from the air, making rooms feel clammy. Both oversized and undersized units use more energy to run, which increases wear and tear on the system and affects comfort.

If your system short cycles or constantly runs, it may not be correctly sized for your living space. Call One Hour Air Conditioning & Heating of Birmingham to assess the cooling capacity of your air conditioner and determine the optimum capacity needed to keep your home comfortable.

Leaking or Blocked DuctsOne Hour Air Conditioning & Heating technician performing AC unit maintenance outside a home in Birmingham, AL, ensuring optimal cooling system performance. Which AC Repairs Are the Most Common?

Ducts distribute conditioned air throughout the living space. Leaking ducts allow up to 30% of this air to escape. Blocked ducts prevent the distribution of air and can affect the pressure and airflow through your home. Both situations make the compressor work harder to deliver conditioned air and keep you comfortable. If you notice a drop in the amount of air coming through ducts, ensure that ducts are open, clean and clear of furniture, drapery or other items.

If you suspect a duct leak, call the technicians at One Hour Air Conditioning & Heating of Birmingham to inspect them. Repairing ducts is best left to trained professionals who have the tools and expertise to locate holes and repair them. The Environmental Protection Agency recommends sealing ducts to enhance energy efficiency and comfort.

Incorrect Thermostat Settings

The thermostat serves as the brain of an HVAC system, communicating with components to set temperatures, control fan speeds and signal when to run and shut down. A thermostat should be located about five feet above the floor on an interior wall away from drafts, direct sunlight, other heat sources and windows. Because the thermostat sensor responds to heat and air currents, the device messages the system when it registers the set temperature. A malfunctioning or improperly placed thermostat will send improper messages that affect performance and comfort.

Adjusting fan settings on the thermostat also affects comfort and airflow. A fan set to “on” will run continuously. A fan set to “auto” runs only when the air conditioner is running and shuts off when the set temperature is reached. Air does not circulate when you use the “auto” setting, which can make rooms feel stuffy and create hot or cold spots.

If your air conditioner is running but not blowing cold air, the problem may be a malfunctioning fan. Our technicians will check the thermostat to ensure it is set properly and that the fans and sensor work.

Importance of Maintenance

During an air conditioner maintenance session, technicians evaluate every part of the heating and cooling system. We check the filters, coils, thermostat, fans, condensate lines, electrical connections and ducts. We also check the pressure and airflow. Catching small problems before they become big problems saves money and energy and provides peace of mind.

If your air conditioner is constantly running but not cooling the air, call Birmingham’s go-to HVAC service professionals at One Hour Air Conditioning & Heating. Our fast, reliable air conditioning repair services will restore comfort quickly and efficiently. We are serious when we say we’re on time or you don’t pay a dime.

We repair, install and maintain all types of heating and cooling equipment, including ducted systems, heat pumps, furnaces and ductless mini-splits. We are available 24/7 for emergency repairs. We back our work with a customer service guarantee for workmanship and parts.

Call One Hour Air Conditioning & Heating today for all your air conditioning and heating needs.